Giant magneto-caloric effect near room temperature in Ni-Mn-Sn-Ga alloys

Abstract

We report the observation of giant magneto-caloric effect (MCE) in ferromagnetic shape memory alloys (FSMAs) of nominal compositions Ni${}_2$Mn${}_{1.36}$Sn${}_{0.64-x}$Ga${}_x$ ($x$ =0.24, 0.28 and 0.32). Irrespective of the Ga doping, all the samples undergo long range ferromagnetic ordering below around 330 K. However, the martensitic transition temperature ($T_{MS}$) of the samples varies strongly with Ga concentration. Clear signature of field induced transition around $T_{MS}$ is visible for all the samples. The observed MCE ($\Delta S$ = 13.6 J/kg K for field changing from 0 to 50 kOe) is found to be highest for $x$ = 0.28 with peak near 249 K, while $x$ = 0.32 shows $\Delta S$ = 12.8 J/kg K at 274 K. This series of Ga-doped alloys are found to be interesting materials with high value of $\Delta S$ over a varied range of temperature

8 pages, 4 figures

References in corpus (4)

• Magnetic superelasticity and inverse magnetocaloric effect in Ni-Mn-In
• Reentrant spin glass state in Mn doped Ni2MnSn shape memory alloy
• Effects of hydrostatic pressure on the magnetism and martensitic transition of Ni-Mn-In magnetic superelastic alloys
• Tailoring magnetic and magnetocaloric properties of martensitic transitions in ferromagnetic Heusler alloys

Cited by in corpus (1)

• Origin of magnetic interactions and their influence on the structural properties of Ni2MnGa and related compounds